Electric starter



1936- A. cALLsEN ET AL 2,041,225

ELECTRIC STARTER Filed March 17, 1934 Patented. May 19, 1936 I a Q UNITED STATES PATENT OFFICE.

ELECTRIC STARTER Albert Callsen and Anton Schmid, Stuttgart,

Germany, assignors to Robert Bosch Aktiengesellschaft, Stuttgart, Germany Application March 1'7, 1934, Serial No. 716,054 In Germany April 25, 1933 2 Claims. (CL 74-7) This invention relates to electric starters for e is axially rotatable on the shell but held against internal combustion engines of the type wherein rotation relative thereto by means of key I. Ara friction ring attached to the engine flywheel is ranged between this disk and the shell are a pluadapted to be gripped in driving engagement berality of strong spring disks or washers g. On 5 tween a pressure shell adjustable on the starter theside away from the shell the disk e is provided 5 shaft and an opposite disk also mounted on the with a cam track it on which run the rollers i. shaft. The rollers are carried in a holder k wedged onto In the previous constructions of this type it the armature shaft. In order to save space the has been proposed to position the pressure shell holder is positioned under the winding heads m and its adjusting mechanism on the side of the of the motor armature a. A ring n is keyed on 10 friction ring away from the starter; that is, upon the end of the armature shaft 2) and held fast by the freev end of the starter shaft. A number of nut o. This ring n'provideslthe opposing disk of disadvantages arise from such a construction, it the friction gearing between the facing surfaces being found that under certain circumstances of which lies the friction ring p of thefiywheel 1.3 the gripping mechanism is not quicklyr'eleased of an internal combustion engine. from the friction ring when the engine starts. The advantages of the invention consist in the Also the diameter of the pressure shell and the fact that the starting motor shaft is journaled parts rotating therewith is limited by the engine between those places at which the starting moflywheel lying in the same plane, wherefore the ment of the shaft is carried over to the pressure inertia of the shell is too small and starting of v shell and the opposing disk n so that the free 20 the friction gearing more diflicult. Furthermore, carrying length of the armature shaft is short a large part of the turning moment upon starting from the journal to the point of power applicathe engine must be carried by the free portion tion. of the starting shaft projecting beyond the bear- The construction is further advantageous in ing of the starting motor. Under great loads this that the shell with its actuating mechanism is may result in bending of the shaft and jamming substantially contained within the motor housing of the gearing. whereby the same is fully protected and consider- It is the principalobject of this invention to able space saved. It is also advantageous in that eliminate these disadvantages. To this end it is it is not necessary to limit the diameter of the 33 a feature of the present invention to journal the torque disk e as would be necessary if the same .30 pressure shell in the starter bearing whereby only were placed on the outer end of the armature the opposite disk and'the part of the pressure shaft 12 where a large diameter would not be pershell coming into contact with the friction ring mitted because of its proximity to the engine flylie beyond the bearing. wheel. This permits suflicient swing to be given 35 Qtherob ects will n part be obvious and in part to assure connecting in of the friction gear. The 35 be pointed out hereinafter. large diameter of the disk also permits the use To the attaining of the aforesaid objects and of plates or disks 9 for springs which may be ends the invention still further resides in the nov,- easily set for any desired spring pressure and el details of the construction, combination and make it possible to'obtain great spring pressure 40 arrangement of parts all of which will first be in small space. 2

fully described in the following detailed descrip- The above described construction also permits tion and. then be particularly pointed out in the a better arrangement when installed, which will appended claims, reference being made to acbe appreciated whenit is remembered that in companying drawing which represents a longimany vehicles the space around the flywheel is tudinal section with parts shown in side elevavery limited and therefore the construction of 45 tion of the flywheel end of a starting motor conthe starter must remain as small as possible. The structed in accordance with the present invenreduction in the size of the part extendi t yond the housing of this starter is therefore a In the embodiment shown in the drawing a indecided advantage.

dicates the armature in the electric starting mo- Having thus described the invention what is 50- tor and b the armature shaft. Sleeve 0, which claimed as'new is: forms the Pressure h is rotatable 0 heh ft 1. In an electric starter "for internal combusb and is also slidably journaledin t e beari g d tion engines, a friction ring mounted on the fly- 0f the Starter that the armature Shaft is jollrwheel of the engine, a starter shaft, a disk mount- 5 naled .in bearing (1 by means f t Shell- A disk ed thereon adjacent one side of said friction ring,

disk and shell.

2. In an electric'starter for internal combustion engines, a friction ring'mounted on the flywheel of the engine, a starter shaft, a disk thereon adjacent one side of said friction ring, a pressure shell surrounding said shaft and iournaled in a bearing thereof on the opposite side of said friction ring and adjustable longitudinally of the starter shaft, and cam gearing including a cam disk having a high inertia adjustable but not rotatable on said pressure shell for adjusting the same, said cam gearing being arranged in the starter.

ALBERT CALL-SEN. ANTON SCHMID. 4 

